Setup Add to cart = redirect to checkout

How to Setup Add to cart and redirect to checkout in Prestashop ecommerce cms ?

Here is a simple way if you want your customers to redirect to shopping cart summary when they are clicked the Add to Cart button.

Go to the configuration page of the "Cart block" and change "Ajax cart" to "No". Also, go to the Preferences > Products tab and make sure "Re-direction after adding product to cart" is set to "cart summary".